Lightsage Raises $4 Million to Help Software Companies Sell Directly to AI Agents

Lightsage, a startup building infrastructure to help software companies make their products discoverable and purchasable by autonomous AI agents, has raised $4 million in seed financing, the company confirmed on September 8, 2026. Nexus Venture Partners led the round, with participation from a notable group of technology-industry angel investors, including Postman chief executive Abhinav Asthana, DocuSign president Robert Chatwani and former Salesforce chief technology officer Steven Tamm.

The startup, formerly operating under the name API-Rex, is betting on a structural shift in how software gets discovered and purchased. Traditional software-as-a-service products are marketed toward human developers and business decision-makers through websites, sales teams, app marketplaces and search engine optimisation. But as increasingly capable coding agents and autonomous AI assistants take on tasks that previously required direct human research and evaluation, the entities selecting which APIs, libraries and services to use in a given task are, in a growing number of cases, software agents rather than human buyers.

Lightsage aims to help software vendors present machine-readable information about their products that allows AI agents to understand a product's capabilities, evaluate whether it fits a given task, and potentially initiate usage autonomously — without requiring a human to manually discover, evaluate and select the service through conventional research channels. The company's premise draws a direct parallel to earlier shifts in software distribution: search-engine optimisation emerged because businesses needed their websites to be discoverable by Google's search algorithms, and app-store optimisation followed as mobile platforms became the dominant discovery channel for consumer software.

If autonomous AI agents increasingly become significant selectors of software and services on behalf of both individual consumers and enterprise users, an entirely new distribution and optimisation layer — sometimes described within the industry as 'agent discovery' or 'agent-readiness' — could emerge, in which software vendors compete to become the default service an AI agent selects automatically when carrying out a relevant task, rather than competing primarily for direct human attention and clicks.

The involvement of prominent operator-angels from established software companies, including Postman, DocuSign and Salesforce, lends Lightsage's early positioning added credibility within the developer-tools and enterprise-software community, suggesting that experienced technology executives view the agent-commerce thesis as a credible enough shift to warrant early personal investment, even though the category remains nascent and its ultimate scale unproven.

Lightsage remains an early-stage company, and the broader thesis underlying its business model — that autonomous AI agents will meaningfully reshape software discovery and purchasing decisions — is still being tested across the industry. Nonetheless, the startup's core premise reflects a question increasingly facing software-as-a-service companies more broadly: as coding agents such as Claude Code, Microsoft Copilot and Cursor take on a growing share of technical decision-making previously handled by human developers, what happens to customer acquisition strategy when the buyer, or at least the recommender, is itself a piece of software rather than a person.